Cardiac Contractility Modulation — EECC MCQ
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Correct answer: E — CCM delivers non-excitatory electrical signals to the RV septum during the absolute refractory period, enhancing calcium handling and contractility without causing additional cardiac contractions — it may be considered for symptomatic HFrEF patients in sinus rhythm with narrow QRS who are not CRT candidates
Cardiac contractility modulation (CCM, Optimizer system) is a device-based therapy that delivers high-voltage biphasic electrical signals during the myocardial absolute refractory period. Unlike CRT (which provides electrical resynchronisation), CCM enhances calcium handling at the cellular level (increasing phospholamban phosphorylation and SERCA2a activity), improving contractility without causing additional beats. The FIX-HF-5C2 trial showed improvement in exercise capacity, quality of life, and NYHA class. The ESC 2023 HF Guidelines include CCM as an emerging therapy (Class IIb) for: symptomatic HFrEF (LVEF 25-45%), sinus rhythm, QRS <130 ms (i.e. patients who do NOT qualify for CRT). The device is implanted similarly to a pacemaker (two RV leads, generator in subcutaneous pocket). It does not provide pacing, defibrillation, or CRT.
Reference: ESC (2023): HF Guidelines; FIX-HF-5C2 Trial